As will be understood, it is conventional in the use of a lathe to maintain a supply of or set of collet chucks of varying dimensions for use on the lathe spindle to accommodate different sized workpieces. As will be appreciated further, each individual collet chuck will accommodate workpieces of varying diameters within a specific range. Nevertheless, although a set of such collect chucks will accommodate a fairly wide range of diameters of workpieces, it is not unusual to come across a workpiece of a diameter or shape for which there is no collet on hand.
In the past, in order to accommodate these "emergency" situations, aside from delaying operations to the extent necessary to purchase a properly dimensioned collet chuck, the usual procedure is simply to utilize a "blank" or undrilled collet chuck which is then machined or "customized" by the operator so that it will receive the workpiece. Such blank or undrilled collets are expensive because they still must be properly prepared initially when they are produced to be received into the spindle including machining the threads and outer cam surfaces adjacent the front of the collet. This preparation is expensive when the collet is to handle perhaps, only a single unusually shaped or dimensioned workpiece, or several in one run of work. Moreover, the internal machining of the blank to receive the workpiece must then be carried out. Moreover, the changeover time is longer.